Method of making a compressed rubberized hair pad



Nov. 17, 1964 H. A. HOWARD 3,156,965

METHOD OF MAKING A COMPRESSED RUBBERIZED HAIR PAD Filed Nov. 27, 1961 5 Sheets-Sheet 1 Nov. 17, 1964 H. A. HOWARD 3,156,955

METHOD OF MAKING A COMPRESSED RUBBERIZED HAIR PAD Filed Nov. 27, 1961 5 Sheets-Sheet 2 Nov. 17, 1964 H. A. HOWARD 3,156,955

METHOD OF MAKING A COMPRESSED RUBBERIZED HAIR PAD Filed NOV. 27, 1961 5 Sheets-Sheet 3 Nov. 17, 1964 H. A. HOWARD 3,156,955

METHOD OF MAKING A COMPRESSED RUBBERIZED HAIR PAD Filed Nov. 27, 1961 5 Sheets-Sheet 4 Nov. 17, 1964 H. A. HOWARD 3,156,965

METHQD OF MAKING A COMPRESSED RUBBERIZED HAIR PAD Filed NOV. 27, 1961 5 Sheets-Sheet 5 United States Patent 3,155,965 METHOD OF MAKING A COMPRESSED RUBBEREZED HAIR PAD Harold A. Howard, London, England, assignor to The Hairlok Company Limited, London, England Filed Nov. 27, 1961, Ser. No. 155,050 Claims priority, application Great Britain, Dec. 1, 1960, 41,324/60 5 Claims. (Cl. 28-42) This invention relates to rubberized hair, primarily for shock-absorbing packaging.

Rubberized hair consists of a mass, usually in the form of a uniform layer or pad, of upholstery fibres intermingled with a relatively open texture, i.e. not dense like felt, and adhesively held together by a coating of an adhesive which remains flexible when dry. The upholstery fibres may be natural fibres such as horsehair or other animal hair, such as wool or vegetable fibres such as coconut fibre or Algerian grass or may be synthetic fibres, for example polyamide filaments. The adhesive may be rubber latex or any other adhesive remaining flexible when dry, for example plasticized polyvinyl chloride.

Any upholstery material of the above described kind coated with an adhesive which remains flexible when dry is included in the expression rubberized hair used in this specification. Also, the term hair includes any other fibre used in making an equivalent product.

For use in shock-absorbing packaging, pads of rubberized hair may be moulded to shape but also extensive use is made of pads cut from sheets or mats of rubberized hair.

In the manufacture of rubberized hair, it is known to start with curled hair which is carded and then, before or after being coated with liquid adhesive, deposited as a layer, or superposed layers, on a supporting surface to form a sheet. If a low density, easily compressible, pad is required, the sheet may be built up to a total thickness which is equal to, or only slightly greater than, the required thickness of the finished pad. If a high density pad, capable of supporting relatively heavy loads, is required, the built-up thickness is made substantially greater and then reduced by compression to the required finished thickness. or more built-up layers, with or without compression to a required thickness, is then given permanent shape by setting of the adhesive, such as by vulcanization in the case of rubber latex adhesive. The sheet may itself form the required pad or may be cut into pads of a required size.

In their deposition into sheet form, the hairs become arranged to a large extent in planes parallel to the plane of the supporting surface and any compression of the built-up thickness accentuates this by flattening upstand ing curls or coils of hair.

If a rubberized hair pad is used in a fiat position, i.e. to support a load acting in the same direction as that in which the component hairs or layers of hair have been superimposed in manufacture, its resilient resistance to compression under the load is relatively low in relation to the mass of the rubberized hair. In order to obtain a higher load-bearing capacity with a given mass, it is known to use pads, usually made from sections cut from sheets, on edge so that the hairs extend predominantly in the direction of the load.

The performance of shock-absorbing pads can be measured, by a series of drop tests, and their optimum value thus determined is expressed in terms of g. In a typical case the value of g for a pad of a given mass used fiat and then on edge has the ratio 9:20. Consequently, for some purposes pads used on edge are too stiff, and

The sheet of hair, composed of one are moreover liable to develop high-frequency oscillations in some uses, so that there is a requirement for rubberized hair pads with an intermediate value in terms of g.

Since the marked difference in performance of a rub berized hair pad flat and on edge is associated with the predominant orientation of the hairs being respectively perpendicular and parallel to the direction of the load, it can be appreciated that an intermediate performance, with more uniform characteristics, should be obtainable if predominance of any one orientation of the hairs could be avoided. The present invention is based on this realization and provides a compressed rubberized hair pad in which the orientation of the hairs is multidirectional. The invention also provides a method and apparatus for producing such a pad.

It should here be mentioned that it is possible to make a rubberized hair pad having a uniform structure, without any predominant orientation of the hairs, by initial 1y assembling carded hair otherwise than by deposition of hair to form a sheet, for example by teasing bunches of hair together, thus avoiding a laminar structure in the body of hair, and also avoiding any substantial compression or compacting of the hair which would cause flattening of the hairs themselves. Such a pad is however of very low density, suitable for only light packing, and is expensive to produce because it involves careful assembly or manipulation of the hair.

For most shock-absorbent. packaging requirements, relatively dense rubberized hair is required and this has usually been made by building up layers of hair, with or without additional compression, during manufacture. It is with such relatively dense rubberized hair that the present invention is concerned.

According to the invention, in a pad of compressed rubberized hair having substantially plane parallel faces, the hairs extend multi-directionally between the plane faces with a sinuous grain resulting from lateral compression, in a direction substantially parallel to the plane faces, applied at closely spaced intervals within the thickness of the pad during manufacture of the pad and before setting of the adhesive of the rubberized hair.

A pad in accordance with the invention can be distinguished from previously known compressed rubberized hair pads by the fact that it is resiliently stretchable or extensible in the direction in which it has been laterally compressed, the sinuous grain structure of the hairs being capable of opening out and closing rather like a concertina. In previous compressed rubberized hair pads, a substantial proportion of the hairs lie in such an attitude and are bonded, by the adhesive, to other hairs in such a way that for part of their length at least they form inextensible links between adjacent portions of the pad which therefore cannot be stretched appreciably without tearing of such hairs or their bonds.

The method according to the invention for making a pad of compressed rubberized hair comprises subjecting a sheet, consisting of at least one layer of hair, to lateral compression applied at closey spaced intervals within the thickness of the sheet and in a direction substantially parallel to the plane of the sheet and subsequently effecting setting of the adhesive of the rubberized hair to maintain the laterally compressed condition thereof.

The preferred method of applying the lateral compression is by means of at least two spaced sets of needles which are inserted into the sheet in a direction perpendicular to the plane thereof and then moved laterally towards each other.

Thus, hairs which have been deposited to form the sheet so that they lie substantially parallel in the plane thereof, and therefore substantially perpendicularly between the inserted needles, become waved or crimped by j the needles moving towards each other and the hairs composing the sheet are caused to assume a predominantly sinuous configuration or grain.

Moreover, when previously-curled hair is used for making the sheet, as is usual, it is found that strands and coils of hair, which become flattened in the formation of the sheet, are caused to bend, kink and open out their coils or curls under the lateral thrust of the needles.

The effect of lateral compression applied at relatively closely spaced intervals Within the sheet of hair is quite different from that which would be produced by any attempt to apply a compression laterally to the sheet of hair as a whole. Such an attempt would result only in a non-uniform compacting of the hair, concentrated near.

the external surfaces at which the compression was applied and less further away according to the inertia of the hair and its friction against the surfaces supporting and confining it.

The lateral compression applied in accordance with the invention, and which may be effected without the sheet of hair having been compressed in thickness or after an initial compression in thickness, tends to increase the thickness of the sheet. The final, finished pad, thickness of'the sheet of hair can be determined by limiting such increase of thickness under the effect of lateral compression or by applying a final, relatively light, compression in thickness.

To enable the finished thickness of the laterally compressed pad to be controlled and the faces of the pad to be made substantially plane, the invention can be carried out by locating the sheet of hair between a pair of multiple-slotted parallel plates, passing the sets of needles. through the slots of the plates and the sheet of hair between them and moving the sets of needles laterally toward one another while the separation of the plates is limited, such as by the weight of one plate resting on distance pieces supported by the other plate.

The method of the invention may be applied in batch production or in continuous sheet production of rubberized hair using apparatus which basically comprises a pair of multiple-slotted parallel plates, to confine the sheet of hair between them, at least two sets of parallel needles carriedby parallel bars, means for effecting relative movement of the pair of plates and the needle bars to thrust the needles through, and subsequently withdraw them from, the slots of the plates and the sheet of hair between them, means for moving the needle bars laterally towards each other while the needles extend through the sheet of hair, and means for holding the sheet of hair in laterally compressed condition after withdrawal of the needles therefrom.

An example of such apparatus and the production of a rubberized hair pad in accordance with the invention will now be described with reference to the accompanying drawings, in which: 1

FIG. 1 is a perspective sketch of a cut piece of a compressed rubberized hair pad such as is well known.

FIG. 2 is a corresponding view of a cut piece of a pad according to the present invention.

FIG. 3 is a view showing the piece of pad of FIG. 2 stretched in the direction indicated by the arrows so as to open out its sinuous grain hair structure.

FIGS. 4, and 6 are respectively a plan, with parts omitted to facilitate illustration, a front elevation and a sectional end view, on the line VlVI of FIG. 4, with parts in alternative positions, of an apparatus according to the invention, and

FIGS. 7, 8 and 9 are diagrams illustrating the sequence of operation of the apparatus.

FIG. 1 shows part of a known kind of compressed rubberized hair pad, the nearer edges 1 and 2 being cut edges to reveal the predominantly plane laminar orientation of the hairs which results from deposition of the hairs in one or more layers and, usually, compression in thickness to increase the density of the pad. In a compressed or moulded pad, the'hair structure is usually concealed by surface compacting of the hair at the edges and it is for this reason that cut edges are illustrate FIG. 2 shows, for comparison with FIG. 1, a similar part of a laterally compressed rubberized hair pad according to the invention, the lateral compression having been effected at relatively closely spaced intervals as indicated by the short arrows. As can be seen at the cut nearer edge 3, such lateral compression has given the hairs a predominantly sinuous grain in the direction of the compression and at the cut nearer edge 4 the orientation of the hairs, transverse to the direction of lateral compression, is multi-directional with substantial proportions extending in the directions of both the thickness and the plane of the pad.

If the part pad of FIG. 2 is stretched in the direction of the lateral compression, as indicated in FIG. 3 by the long arrows, the sinuous structure opens out, somewhat in the manner of a Concertina, and the sinuous structure is more easily recognizable. Such stretching is not possible with known pads of the kind illustrated by FIG. 1.

In a pad laterally compressed by inserted needles in accordance with the invention, it may happen that the needles leave small but defined holes in the pad as indicated by 5 in FIG. 2.

Apparatus for the batch production of pads is shown by FIGS. 4, 5 and 6 and comprises a frame 6 in which a horizontal pair of multiple-slotted plates, or grid tables, 7 and 8 are located and verticallyrmovable. I

The lower plate 7 is carried by raising and lowering mechanism, shown as a hydraulic or pneumatic jack 9,

and the upper plate 8 can rest freely on adjustable supports 10 or can be raised, by the lower plate 7, to be engaged and releasably held up by pneumatic or like,

retractable plunger locks 11 at each side of the frame 6. The alternative, lowered and raised, positions of the plates 7 and 8 are shown respectively by the left and right parts of FIG. 6.

In the upper part of the frame 6, two pairs of guide rods 12 extend horizontally from side to side, one pair at the back and the other pair at the front, and on the rods 12 are slidably mounted, by hearing sleeves 13, a large number of closely-spaced horizontal parallel bars 14 from each of which projects downwardly a set of vertical needles 15.

The bearing sleeves 13 alternate on the pairs of rods 12, which permits relatively long sleeves to be used.

The bars 14 are linked together in adjacent pairs by inclined slotted links 16 so that the bars can slide, on the guide rods 12, towards each other into mutual abutment or apart to the limit of the slots of the links 16.

At each end of the assembly of bars 14, a beam 17 is also mounted to slide on the guide rods 12, is linked by slotted links 18 to the respective end bar 14 and has a straight rack 19 extending transversely over the bars 14 to mesh with a vertical axis pinion 20, the two racks being at opposite sides of the pinion, on a shaft 21 which has a bevel gear 22 to be driven by a reversible electric motor 23.

By rotation of the pinion 20 in one direction, the beams 17 can be moved inwardly to abut against the respective end bars 14, entrain such end bars in their movement and cause them in turn to abut against and move successive bars until the assembly of bars has been closed towards the centre.

On reversal of the pinion 20, the beams 17 are moved outwardly, pulling the bars 14 successively apart through the links 18 and 16.

Rotation of the pinion 24) is controlled by suitable switches for the electric motor 23 and these may include manual starting and reversing switches and auto-' matic stopping switches, such as are known as limit switches, operated by contact with the beams 17 at suitable positions on the frame 6.

The operation of the apparatus will now be described with reference to the diagrams, FIGS. 7, 8 and 9.

A sheet of hair coated with adhesive is prepared, for example is cut from a web of such hair produced in a manner known for rubberised hair, and is placed on the lower plate 7 of the apparatus when the plates are in the lower osition as shown in FIG. 5.

By operation of the jack 9, the lower plate 7 is raised and lifts the upper plate 8, resting on suitable distance pieces placed on the lower plate 7 to suit the required finished thickness of pad, until the needles 15 have passed through the slots in the plates and the sheet or" hair between them. This position is shown by FIG. 7 in which the sheet or" hair is shown by reference 24.

The motor 2.3 is now operated to cause the needle bars 14 to close together so that the needles laterally compress the sheet of hair at closely spaced intervals. During this lateral compression, increase in thickness of the hair sheet is limited by the spacing and weight of the upper plate 3, and t e hair sheet fiattens its upper and lower faces against the plates 7 and 8.

The plunger locks 11 are now protruded to engage and support the upper plate 8 in its raised position and the lower plate 7 is lowered, leaving the latera ly compressed sheet of hair impaled on the needles 15 as shown by FIG. 8.

An open rectangular frame 25 is placed on the lower plate 7, in alignment below the laterally compressed hair sheet 24, as shown in FIG. 8 and the lower plate is again raised for the frame 25 to surround the sheet 24.

The plunger locks 11 are now retracted and the lower plate 7 lowered, carrying with it the frame 25, the sheet 2'? therein and the upper plate 8 until the plate 8 encounters and rests on the supports 1%. This position is shown by FIG. 9.

The sheet 24, recovering slightly from its lateral compression, fits tightly in the frame 25 and can be removed therewith. Subsequent vulcanization, or other setting of the adhesive, renders permanent the laterally compressed state of the hair sheet which, after removal from the frame 25, forms the required pad.

For continuous production, a basically similar method to that described above can be used, the needle bars in such case being, for example, slats of an endless chain or belt which is lowered on to a sheet of hair moving on a conveyor, between multiple-slotted parallel plates, so that the needle slats travel with, successively close up to one another and compress the hair at intervals in the direction of travel until it has passed through a vulcanizing chamber or other setting stage.

In another method of continuous production a sheet of hair, coated with liquid adhesive and being conveyed in a direction in its plane, is compressed in a direction in its plane at relatively closely spaced intervals by means of at least one pair of sets of needles which are caused repeatedly to penetrate the sheet in the direction of its thickness, relatively moved, one set laterally towards the other for a short distance, and then withdrawn from the hair.

The effect of the sets of needles each time they move towards each other is to compress laterally the portion of hair between them and, movement of the sheet being maintained at a suitably reduced speed, such compression is held until vulcanization or other setting of the adhesive renders the compression permanent.

t will be understood that other arrangements could d be used for successively closing together needles or equivalent hair-engaging members so as to ellect in a sheet of hair successive or simultaneous local and limited compressions of the hair laterally with respect to the plane of the sheet.

For example, two parallel bars, each with an array of needles, may be mounted on a conveyor for the rubberized hair sheet and caused, by links and eccentric or cam motions, repeatedly to penetrate the hair and carry out the desired cycle of movement.

One bar may simply be given a reciprocating movement, for its needles intermittently to enter the hair as a stop for hair compressed by the needles of the other bar which is given a lateral movement as well as a reciprocation.

Alternatively, and preferably, both bars are given a similar reciprocating and lateral movement, but opposite in direction in the lateral movement, so that they both move to compress hair between their needles.

The needles of each pair may be arranged to penetrate the hair both from the same side of a sheet, for example downwardly with a horizontally-conveyed sheet, or from opposite sides, for example from above and below a horizontally-conveyed sheet or from either side of a vertically-conveyed sheet.

A pad of rubberized hair made in accordance with the invention can be seen, particularly by inspection of a section cut in the direction of the lateral compression, to have a hair structure which is not predominantly plane-laminar, like ordinary layered rubberized hair, but multidirectional and with a Wavy or sinuous grain in the direction of the lateral compression.

I claim:

1. A method of making a pad of compressed rubberized hair comprising subjecting a sheet, consisting of at least one layer of adhesive coated hair, to lateral compression applied at closely spaced intervals within the thickness of the sheet and in a direction substantially parallel to the plane of the sheet and subsequently effecting setting of the adhesive coating of the hair to maintain the laterally compressed condition thereof.

2. A method according to claim 1, in which the lateral compression is applied by means of at least two spaced sets of needles which are inserted into the sheet in a direction perpendicular to the plane thereof and then moved laterally towards each other.

3. A method according to claim 2, in which increase of thickness of the hair sheet, under the effect of the lateral compression, is limited.

4. A method according to claim 3, in which the sheet of hair is located between a pair of multiple-slotted parallel plates, the sets of needles are passed through the slots of the plates and the sheet of hair between them, and the sets of needles are moved laterally towards one another while the separation of the plates is limited.

5. A method according to claim 1, in which the lateral compression of the sheet of hair is elfective after the hair has been coated with adhesive.

References tilted in the file of this patent UNITED STATES PATENTS 1,992,603 Burgess Feb. 26, 1935 2,198,724 Schreiner Apr. 30, 1940 2,845,687 Howard Aug. 5, 1958 2,896,303 Morrill July 28, 1959 2,974,393 Hollowell Mar. 14, 1961 

1. A METHOD OF MAKING A PAD OF COMPRESSED RUBBERIZED HAIR COMPRISING SUBJECTING A SHEET, CONSISTING OF AT LEAST ONE LAYER OF ADHESIVE COATED HAIR, TO LATERAL COMPRESSION APPLIED AT CLOSELY SPACED INTERVALS WITHIN THE THICKNESS OF THE SHEET AND IN A DIRECTION SUBSTAN- 